With rapid diversification of the social environment in recent years, an increasing number of people are suffering from anxiety, and it has been expected to develop psychosomatic therapies and excellent therapeutic agents.
Benzodiazepine compounds such as diazepam have found wide use of anxiolytics. This group of agents, however, generally have side effects such as hypnotic effect, muscle relaxant effect and sedative effect. Serotonin anxiolytic agents such as buspirone are also recently developed as anxiolytics which are different from the benzodiazepine compounds in activity mechanism. Reportedly these serotonin agents are generally lesser than the benzodiazepines in side effects such as hypnotic, muscle relaxant and sedative effects, but they are lower in anxiolytic effect and have the problems of diminishing voluntary movements presumably owing to their activity as a dopamine antagonist, and causing serotonin syndrome which appears attributable to their properties as a full agonist for serotonin 1A receptor.
On the other hand, the bicyclolactam derivatives of the present invention are known compounds disclosed in International Public Disclosure No. WO 91/11434, and are known to have a cerebral function improving effect, cerebral metabolism activating or anoxic brain damage protecting effect and effect against senile dementia. Nevertheless, nothing whatsover is known about the anxiolytic effect of these compounds.
Anxiety is an essential symptom of neuroses and is a neurotic disorder involving no organic disorder of the brain.
In contrast, the term dementia refers to an organic mental disorder which is the sustained deterioration of acquired intelligence due to an organic disorder of the brain. Many of dementias are caused by a wide variety of organic disorders of the brain and involve general deterioration of mental functions such as memory, calculation, orientation and discretion, leading to failure of correct recognition, judgement or behavior as to one's own situation.
"Diagnostic and Statistical Manual of Mental Disorders," Revised 3rd Ed. (DSM-III-R), widely used as a diagnostic manual and published by American Psychiatric Association in 1987, clearly classifies these diseases in the chapters "Anxiety Disorders (or Anxiety and Phobic Neuroses)" and "Organic Mental Syndromes and Organic Mental Disorders" (see "DSM-IIII-R Classification of Mental Disorders and Diagnostic Manual," (2nd Ed.), translated by Saburo Takehasi et al., published by Tgaku Shoin (1988), pp. 71.about.94 and 121.about.129).
An object of the present invention is to provide a novel anxiolytic agent comprising a bicyclolactam derivative as its effective component, and a therapy of anxiety.